body{
    background-color: darksalmon;
}

.empty{
    display: inline-block;
    height: 160px;
    width: 160px;
    background-color: #fff;
    margin: 5px;
    border: 3px solid salmon;
}

.fill{
    background-image: url("https://source.unsplash.com/random/150x150");
    position: relative;
    height: 150px;
    width: 150px;
    top: 5px;
    left: 5px;
    cursor: pointer;
}

.holder{
    border:5px solid #ccc;
}

.hovered{
    background: #f4f4f4;
    border-style: dashed;
}